聚合物前驱体法合成La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)纳米粉体

Preparation of La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) nano powders by polymeric precursor method

采用聚合物前驱体法,以硝酸盐为原料,乙二醇为溶剂,甘氨酸为螯合剂制备La0.6Sr0.4Co0.2Fe0.8O3-δ前驱体溶胶及其纳米粉体,考察甘氨酸用量、溶胶蒸发温度及时间对溶胶稳定性的影响。结果表明:当甘氨酸和总金属离子物质的量之比为1∶1时,65℃蒸发48 h可得到均匀、稳定的前驱体溶胶;所得凝胶在700℃下烧结5 h可得到平均粒径为54.4 nm的纯钙钛矿型粉体。

La0.6Sr0.4Co0.2Fe0.8O3-δ precursor sol and as-made nano powders were prepared by polymeric precursor method,in which nitrates were used as synthesis materials,ethylene glycol as solvent and glycine as chelating agent.The effects of glycine content,synthesis temperature and synthesis time on the stability of precursor sol were investigated.Results showed that homogenous and stable precursor sol could be synthesized at 65 ℃ for 48 h by a molar ratio of 1∶1 for glycine over total metal cations.Pure perovskite-type powders with average particle size of 54.4 nm could be obtained by calcinating the precursor gel at 700 ℃ for 5 h.